The engine operation in a hybrid electric vehicle (HEV) is significantly different than in a conventional vehicle as the vehicle may be operated using electric power only. In certain hybrids, such as plug-in electric hybrids (PHEVs), battery energy may be prioritized, and the engine may only run for a short time period during a vehicle operation cycle, or from key on to key off.
An HEV or PHEV with a diesel engine require emission control devices and corresponding control strategies for the devices. The diesel aftertreatment procedures or requirements may force more frequent and continuous engine-on operation. Examples of aftertreatment procedures include: diesel particulate filter (DPF) regeneration, catalyst light off, diesel oxidation catalyst (DOC) heat-up, other exhaust temperature maintenance procedures, and maintaining in-use monitor performance ratios (IUMPRs).
Energy management in a diesel PHEV favors reduced or minimum engine-on time to gain fuel economy benefits. There may be additional drivability concerns or expectations, like PHEV users, expecting the engine to be off when the power demand is low and the vehicle speed is low. The aftertreatment procedures need to be completed without significantly impacting fuel economy or drivability.
Various embodiments of the present disclosure provide opportunistic scheduling of some aftertreatment procedures such that they occur during an engine-on window for the vehicle thereby minimally impacting fuel economy and drivability expectations. An engine-on condition may be triggered by events such as a driving power request or battery state of charge (SOC) condition.